Turn on CLANG_IS_CC when not building gcc

[Dag-Erling Smørgrav]

Dimitry Andric <dim at FreeBSD.org> writes:
> Dag-Erling Smørgrav <des at des.no> writes:
> > The following patches (for head and stable/9) automatically enables
> > CLANG_IS_CC if GCC is disabled but CLANG is not.  Any objections?
> This looks fine to me.  Otherwise, if ${CC} isn't set to clang,
> buildworld might fail in mysterious ways... :)

Not mysterious at all - it fails while building xlint in the cross-tools
phase because, while bsd.{lib,prog}.mk invoke the compiler as "clang"
and not "cc", lint itself tries invokes "cc" to generate the lint
libraries (/usr/libdata/lint/llib-l{posix,stdc}.ln).

DES
-- 
Dag-Erling Smørgrav - des at des.no